Every Modbus slave(server) has a Modbus map that defines what is where and typically what format the data is.
Alternatively, when a Modbus master/client reads data from a Modbus slave/server, it has to do something with the data, move it somewhere into some kind of register where it can dealt with.
Most Modbus slave/server maps are fixed; the manufacturer defines what is where. Some Modbus maps are custom, like on some wireless gateways, where the user defines which of the potential tens of thousands of tags are to be used and which tags are in which location.
I haven't a clue what CCW is, but when you use the words 'Modbus map' I think of the registers where internal data resides, but that might not be the way you are using the words.
Are you referring to
- a CCW Modbus map of internal variables (that CCW slave/server presents to the world) or
- where data gets moved to when CCW (as a master/client) reads data via Modbus?